From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6948 invoked by alias); 5 Feb 2008 19:02:17 -0000 Received: (qmail 6862 invoked by uid 22791); 5 Feb 2008 19:02:16 -0000 X-Spam-Status: No, hits=-1.2 required=5.0 tests=AWL,BAYES_50,SPF_HELO_PASS,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 05 Feb 2008 19:01:58 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id m15J1u0f006614; Tue, 5 Feb 2008 14:01:56 -0500 Received: from pobox.corp.redhat.com (pobox.corp.redhat.com [10.11.255.20]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m15J1tY3014894; Tue, 5 Feb 2008 14:01:55 -0500 Received: from localhost.localdomain (sebastian-int.corp.redhat.com [172.16.52.221]) by pobox.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m15J1shH006876; Tue, 5 Feb 2008 14:01:55 -0500 Message-ID: <47A8B28F.6010700@redhat.com> Date: Tue, 05 Feb 2008 19:02:00 -0000 From: Andrew Cagney User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: "Frank Ch. Eigler" CC: systemtap@sourceware.org, frysk Subject: Re: my notes from the tracing workshop References: <47A34AA2.5070404__28393.9727153212$1201883893$gmane$org@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.58 on 172.16.52.254 X-IsSubscribed: yes Mailing-List: contact frysk-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: frysk-owner@sourceware.org X-SW-Source: 2008-q1/txt/msg00051.txt.bz2 Frank Ch. Eigler wrote: >> [...] >> "DB" >> There was a strong consensus that the "internal" format of the log >> data needed to be a fast light weight database; two vendors were using >> sqlite for instance (TPTP the eclipse tool didn't but I suspect will >> shortly). [...] >> > > This seems rather wacky. If they're talking about gigabytes of trace > traffic, a little wee in-memory database is a reach. If you need to > do declarative querying, then you need a real database with indexes > and whatnot. If you just need a big ass array, use BerkeleyDB. If > you just want strongly typed flat data on disk, go XML. I wish I'd > been there - perhaps my perceptions could have been falsified. > > Right, SqLite is a little wee in-process database; it provides a mechanism for powerful queries without the overhead of a server implementation. Wind River presented performance numbers supporting the approaches usability; in particular timing such as populating the database from trace logs. While that cost is real, it is outweighed by the benefit of being able to select arbitrary data-sets for visualization. For system tap, provided the on-disk raw trace data format is well defined, it will be possible to load it into SQL. BTW, while the on-disk format could be XML, there was a general feeling that XML is just too verbose and more compact formats intermediate forms were needed. Can I recommend looking through the relevant slides. > >> [...] What's the status of SystemTAP on the ARM? [...] >> > > I haven't run it personally, but others have (Eugene Teo for the Nokia > N800). One difficulty appears to be finding a big enough ARM box to > self-host the kernel module build process, or else cross-compiling and > cross-running. > Cool, ARM support for libunwind is currently being integrated. Andrew